1. Field of the Invention
This invention relates to a new and improved plastic snap-on type tamper-evident cap and to the neck construction for a container for motor oil or the like closed by such cap.
2. Description of Related Art
Heretofore, motor oil containerrs have been closed by high density polyethylene screw caps by reason of the fact that the product tends to leak through conventional closures. The present invention uses a snap-on cap. Although snap-on caps have been used for such purpose, the structure of such caps is considerably different.
Tamper-evident caps wherein the skirt of the cap is weakened by score lines so that the lower portion of the skirt may be torn away before the cap is removed are well known in the art. Such caps are formed with internal beads which lock under shoulders on the exterior of the container neck. When the lower portion of the skirt is torn away, the remaining (reclosure) portion of the cap may be removed, but when the skirt is intact, the cap cannot be removed without evidence of tampering with the contents appearing.
Interrupted internal cap beads are also known in the art, such beads permitting flexure of the cap skirt so that the container neck is not crushed nor is the cap split.
One conventional means for removing the lower portion of the cap skirt has been formation of a line of minimum or reduced thickness in the wall of the skirt which extends horizontally around the skirt and a depending scoreline extending to the bottom of the skirt, the tear tab being located near the lower end of the depending score line. By pulling the tear tab the skirt tears along the downward-extending tear line and then circumferentially around the horizontal line of reduced thickness. The configuration of the line of minimum thickness comprises a novel feature of the present invention.
To facilitate gripping the tear tab, the lower end of the skirt has been offset in the region thereof so that the tear tab may conveniently be gripped by the thumb or finger of the user.